Radio emission from accreting isolated black holes in our galaxy. Issue 2 (4th July 2019)

• Record Type: Journal Article
• Authors: Tsuna, Daichi; Kawanaka, Norita
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 488:Issue 2(2019)
• Page Start: 2099
• Page End: 2107
• Publication Date: 2019-07-04
• Subjects: accretion, accretion discs -- black hole physics -- Galaxy: general; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stz1809
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: Apart from the few tens of stellar-mass black holes discovered in binary systems, an order of 10 8 isolated black holes (IBHs) are believed to be lurking in our Galaxy. Although some IBHs are able to accrete matter from the interstellar medium, the accretion flow is usually weak and thus radiatively inefficient, which results in significant material outflow. We study electron acceleration generated by the shock formed between this outflow and the surrounding material, and the subsequent radio synchrotron emission from accelerated electrons. By numerically calculating orbits of IBHs to obtain their spatial and velocity distributions, we estimate the number of IBHs detectable by surveys using SKA1-mid (SKA2) as ∼30 (∼700) for the most optimistic case. The SKA's parallax measurements may accurately give their distances, possibly shedding light on the properties of the black holes in our Galaxy.